/* choose.css - 闯关模式难度选择页面样式 */

body {
    background: linear-gradient(135deg, #1a1a2e 0%, #16213e 50%, #0f3460 100%);
    color: white;
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    margin: 0;
    padding: 0;
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
}

.difficulty-container {
    max-width: 800px;
    width: 100%;
    padding: 40px 20px;
}

.page-header {
    text-align: center;
    margin-bottom: 40px;
}

.page-title {
    font-size: 3rem;
    font-weight: bold;
    margin-bottom: 10px;
    background: linear-gradient(45deg, #ff6b6b, #feca57, #48dbfb);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.page-subtitle {
    font-size: 1.2rem;
    color: #ccc;
    margin-bottom: 30px;
}

.difficulty-cards {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 30px;
    margin-bottom: 40px;
}

.difficulty-card {
    background: rgba(255, 255, 255, 0.1);
    backdrop-filter: blur(10px);
    border-radius: 20px;
    padding: 30px;
    text-align: center;
    border: 2px solid transparent;
    transition: all 0.3s ease;
    cursor: pointer;
    position: relative;
    overflow: hidden;
}

.difficulty-card:hover {
    transform: translateY(-5px);
    border-color: rgba(255, 255, 255, 0.3);
    box-shadow: 0 15px 30px rgba(0, 0, 0, 0.3);
}

.difficulty-card.easy {
    background: linear-gradient(135deg, rgba(76, 175, 80, 0.2), rgba(76, 175, 80, 0.1));
}

.difficulty-card.medium {
    background: linear-gradient(135deg, rgba(255, 152, 0, 0.2), rgba(255, 152, 0, 0.1));
}

.difficulty-card.hard {
    background: linear-gradient(135deg, rgba(244, 67, 54, 0.2), rgba(244, 67, 54, 0.1));
}

.difficulty-card.extreme {
    background: linear-gradient(135deg, rgba(156, 39, 176, 0.3), rgba(156, 39, 176, 0.15));
    border: 2px solid rgba(156, 39, 176, 0.5);
}

.difficulty-icon {
    font-size: 4rem;
    margin-bottom: 20px;
}

.difficulty-card.easy .difficulty-icon {
    color: #4CAF50;
}

.difficulty-card.medium .difficulty-icon {
    color: #FF9800;
}

.difficulty-card.hard .difficulty-icon {
    color: #F44336;
}

.difficulty-card.extreme .difficulty-icon {
    color: #9C27B0;
}

.difficulty-title {
    font-size: 1.8rem;
    font-weight: bold;
    margin-bottom: 15px;
}

.difficulty-level {
    display: inline-block;
    padding: 5px 15px;
    border-radius: 20px;
    font-size: 0.9rem;
    font-weight: bold;
    margin-bottom: 15px;
}

.difficulty-card.easy .difficulty-level {
    background: #4CAF50;
    color: white;
}

.difficulty-card.medium .difficulty-level {
    background: #FF9800;
    color: white;
}

.difficulty-card.hard .difficulty-level {
    background: #F44336;
    color: white;
}

.difficulty-card.extreme .difficulty-level {
    background: #9C27B0;
    color: white;
}

.difficulty-description {
    color: #ccc;
    margin-bottom: 20px;
    line-height: 1.6;
}

.difficulty-stats {
    display: flex;
    justify-content: space-around;
    margin-bottom: 20px;
}

.stat {
    text-align: center;
}

.stat-value {
    font-size: 1.5rem;
    font-weight: bold;
    margin-bottom: 5px;
}

.stat-label {
    font-size: 0.8rem;
    color: #999;
}

.difficulty-card.easy .stat-value {
    color: #4CAF50;
}

.difficulty-card.medium .stat-value {
    color: #FF9800;
}

.difficulty-card.hard .stat-value {
    color: #F44336;
}

.difficulty-card.extreme .stat-value {
    color: #9C27B0;
}

.select-btn {
    background: linear-gradient(45deg, #667eea 0%, #764ba2 100%);
    border: none;
    color: white;
    padding: 12px 30px;
    border-radius: 25px;
    font-weight: bold;
    font-size: 1.1rem;
    transition: all 0.3s ease;
    width: 100%;
    margin-top: 10px;
}

.select-btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 5px 15px rgba(102, 126, 234, 0.4);
}

.back-btn {
    background: rgba(255, 255, 255, 0.1);
    border: 1px solid rgba(255, 255, 255, 0.3);
    color: white;
    padding: 10px 25px;
    border-radius: 25px;
    font-weight: bold;
    transition: all 0.3s ease;
    text-decoration: none;
    display: inline-flex;
    align-items: center;
    justify-content: center;
}

.back-btn:hover {
    background: rgba(255, 255, 255, 0.2);
    color: white;
    text-decoration: none;
}

.selected {
    border-color: #feca57 !important;
    box-shadow: 0 0 30px rgba(254, 202, 87, 0.3);
}

.difficulty-info {
    background: rgba(255, 255, 255, 0.05);
    border-radius: 15px;
    padding: 20px;
    margin-top: 30px;
}

.info-title {
    font-size: 1.3rem;
    font-weight: bold;
    margin-bottom: 15px;
    color: #feca57;
}

.info-content {
    color: #ccc;
    line-height: 1.6;
}

@media (max-width: 768px) {
    .difficulty-cards {
        grid-template-columns: 1fr;
    }
    
    .page-title {
        font-size: 2.5rem;
    }
}